"Ser" is used when you're talking about the identity or an intrinsic characteristic of a person; "estar" is used for an attribute that doesn't belong to the person's personality description.

It's rather hard to imagine when I'd say of a person "es enojado", because "enojado" usually implies a specific situation for which one is upset. Nevertheless, there are people who can be described as being "colérico, irritable, iracundo" to indicate that this person is always angry or that they get easily angry, and this is a trait of his own personality.

If I say "soy feliz", it means I identify happiness with my own identity, but if I say "estoy feliz", it implies that something happened to me (something that is not a part of myself) that made me happy for a while.

If someone says "Juan está triste", one must assume there is something that happened to him that made Juan sad; but if there's someone who says "Juan es triste", they're probably talking about a melancholic rather dramatic personality.

Small example:
You have just met Mr. López, and you describe him: "El señor López es calvo y gordo."
Mr. López' brother describes him: "Mi hermano está calvo y gordo."
The difference in the chosen verbs is because if you have just met Mr. López, you may assume (consciously or not) that he has always been bald and fat, while for his brother, who knew him when he had long hair and was thin, these are characteristics that do not belong to the identity of his brother.

I hope this helps.

__________________♪ ♫♪Ain't it wonderful to be alive when the Rock'n'Roll plays... ♪♫♪

I wonder if it would be a good idea to make a new sticky thread (or a vocabulary by theme thread?) looking at the changes in meaning that can happen when exchanging ser vs. estar + an adjective or participle. Let me give a few of the examples that I have run across for a start: